This invention relates to an electric transformer and, more particularly, to a transformer having a core of amorphous ferromagnetic alloy.
Traditionally, the cores of electric transformers have been made of grain-oriented silicon steel laminations. In recent years, however, amorphous ferromagnetic alloy has been increasingly used in such applications in order to decrease core operating losses. This amorphous alloy is available in the form of very thin strip material which is quite brittle, especially after annealing. Using this strip material for core laminations, it is very difficult to make a laminated amorphous alloy transformer core and to incorporate such core in the transformer without some chipping or breaking of the edges of the core laminations. Most such chips can be removed during the manufacturing process, but there is a chance that a small quantity will appear or be developed later.
The presence of loose metal chips in a transformer is very undesirable since such chips can deposit on and short out winding insulation and can reduce the dielectric strength of the insulating oil in the transformer. Either of these conditions can lead to a failure of the transformer.